Anorectal Malformations (Part 3).

(This section is meant for residents to check their understanding regarding a particular topic) QUESTIONS


ANSWERS Answer 1:
The aim of treatment of anorectal malformations is not just to create a passage for stools in the perineum but also to have a child who can have voluntary bowel movements without any medications and without any associated iatrogenic or congenital abnormality such as urinary incontinence.An assessment and appropriate management of urinary system pathologies ( 1) is an important aspect of management of a child with anorectal malformations and has been enlisted as one of the criteria for long term assessment by few researchers.(2)(3)(4)(5)(6) The quality of life of a child with anorectal malformation is thus dependent on the following factors: 1. Fecal continence 2. Constipation 3. Urinary continence/Urinary pathologies The global assessment of long-term outcome of children with various types of anorectal malformations as analysed by Lewitt, et al (7) are tabulated in Table 1.The terminologies used in the outcome analysis are constipation, urinary incontinence and fecal incontinence and must be clearly understood by the students and the researcher before categorizing the patients.

Constipation:
Definition: The North American Society of Gastroenterology, Hepatology, and Nutrition (NASPGHAN) defines constipation as "a delay or difficulty in defecation, present for 2 weeks or more, and sufficient to cause significant distress to the patient."(8) The Paris Consensus on Childhood Constipation Terminology (PACCT) defines constipation as "a period of 8 weeks with at least 2 of the following symptoms: defecation frequency less than 3 times per week, fecal incontinence frequency greater than once per week, passage of large stools that clog the toilet, palpable abdominal or rectal fecal mass, stool withholding behavior, or painful defecation."(9) Lewitt and Pena have graded constipation in children with anorectal malformations as follows: N = Normal (no constipation) 0 = managed with diet restrictions only 1 = managed with laxatives 2 = managed with enemas

Fecal incontinence:
Definition: An inability to hold feces in the rectum due to failure of voluntary control over the anal sphincters permitting untimely passage of feces and gas is defined as fecal incontinence.
In a child with anorectal malformation, total continence is only when there is voluntary bowel movement and no soiling.

Urinary incontinence:
Definition: The inability to hold urine in the bladder due to loss of voluntary control over the urinary sphincters resulting in the involuntary passage of urine is defined as urinary incontinence.A continent child thus must be dry at all times and must void spontaneously.Those who are on CIC and remain dry are termed as pseudocontinent.

Answer 2:
Continence mechanism for feces includes several factors such as - The structural and functional integrity of anorectal unit which is composed of first 4 factors is the key to fecal continence, of which normal anal sphincter function -both the external and internal anal sphincter -are critical parts of continence.(Fig. 1)  The clinical parameters of the child with anorectal malformations can predict and prognos-ticate the long-term outcome of these children which is tabulated in Table 2 and Table 3.

Answer 3:
Several scoring systems exist and the pediatric surgeon can choose any one scoring systems.Globally, there is still no consensus as to the best scoring system and also due to wide variations in extent of the anomaly and an inability to categorise the anomalies, the comparative evaluation is extremely difficult.Table 4 gives an overview of the existing scoring systems and the components assessed in these children.Once a clinical evaluation is done and the severity of the fecal incontinence is assessed by utilizing the scoring system, further investigations are needed to ascertain the exact etiology of fecal incontinence.Depending on the cause of incontinence, treatment in the form of conservative or medical or surgical intervention is planned.Table 5 provides the sequence of diagnostic tests and the management thereof.

Levatoroplasty
+ Bowel management program -many programs exist , choice is as per the severity and feasibility for the parents to carry out the program effectively.++EMG -Author's experience -electromyography of the external anal sphincters done by physiotherapist and severity of sphincteric incompetence assessed, both pre-therapy and post-therapy +++ ART -Anal re-education therapy -Author's experience -which includes strengthening the pelvic musculature and sphincters with regular and monitored exercise regimen coupled with Faradic stimulation of the sphincteric muscles with an individualized protocol depending on the need of the child.
Those children who remain clean/dry on regular bowel management program are pseudo continent.Grades of fecal incontinence: A. Voluntary bowel movements or involuntary escape of feces B. Soiling a. Normal: No soiling b. 1 = minimal, occasional, < 2times a week; no change of underwear required c. 2 = frequent; once a day; frequently requires change of underwear d. 3 = constant

Table 1 :
Long-term outcome of children with Anorectal malformations

Table 2 :
Predictors of prognosis in patients with ARM INDICATORS OF GOOD PROGNOSIS

Table 3 :
Prognostic signs for patients with ARM

Table 4 :
Overview of the scoring systems

Table 5 :
Management of fecal incontinence